If the revelation is that she is dying, then… well, at least we’ll have hiatus to prepare for what would undoubtedly be a tragic twist.
Given that Season 15 will be the end of the show, we may want to brace ourselves for a tragedy.
If the revelation has something to do with a case, her health may not be her biggest problem.
That said, the news that Diana will be back because of “a revelation” in the fourteenth season finale may indicate that she’s not going to die of natural causes, if she dies at all.